UK AIR

Air Information Resource

Air quality indicator for sustainable development 2010 - Final Results

News published: 28/04/2011

The indicators measure annual UK levels of pollution from particulates (PM10) and ozone (O3), the two pollutants thought to have the greatest health impacts, as well as the number of days on which levels of any one of five pollutants were ‘moderate or higher’. These results are an update of those published on 3 February 2011, following the full quality control process.

Overall, the results have changed very little from the provisional publication, although the average number of days of ‘moderate or higher’ pollution at urban sites has decreased from 10 to 8 due to fewer ozone pollution days.

The long-term decrease in urban background particulate concentrations has levelled off in the last two years, remaining at 19 micrograms per cubic metre (µg m-3) since 2008. Roadside levels increased slightly in 2010 to 23 µg m-3, although this followed a relatively large decrease in 2009, and there is an overall decreasing trend.

Rural and urban background ozone concentrations both saw a drop in 2010, to 67 µg m-3 for rural (compared to 68 in 2009) and 53 µg m-3 for urban background (compared to 55 in 2009).

The long-term increase in urban background ozone has shown signs of levelling off in recent years, and has now seen two consecutive years of decrease, to the lowest level since 2001. Rural ozone has also decreased for two consecutive years, although there is still no clear long-term trend.

The average number of days of moderate or higher air pollution for rural sites decreased for a second consecutive year to an average of 22 days, the lowest since 1987. This is driven by a decrease in ozone pollution days. Results are however very variable over time, and there is no clear long-term trend.

Urban sites saw an average of 8 pollution days, down from 10 in 2009 and the lowest since records began in 1993. This followed a larger decrease in 2009, although there is no clear long-term trend.